Please help me solve those

For Q. 73 79: Let X be a continuous random variable with probability density function is given by: k(1x), 0> For Q. 82 84: Suppose that a survey of 500 parents was conducted. The survey asked questions about whether or not the person had a child in college and about the cost of attending college. Results are shown in the table below. Suppose one person is chosen at random. Cost Too Much Cost Just Right Cost Too Low Child not in College 0.20 0.25 0.11 (82) The probability that the person thinks college cost is just right given that he has a child in college. | (A) 0.5 (B) 0.295 (C) 0.13 (D) 0.34 | (E) none of these (83) The probability that the person does not have a child in college given that he thinks college cost is too low. (A) 0.242 (B) 0.38 (C) 0.196 (D) 0.11 (E) none of these